diff --git a/vendors/ligo-utils/simple-utils/cover.sh b/vendors/ligo-utils/simple-utils/cover.sh
index b7331dd37..da8f25894 100755
--- a/vendors/ligo-utils/simple-utils/cover.sh
+++ b/vendors/ligo-utils/simple-utils/cover.sh
@@ -87,6 +87,15 @@ while : ; do
       no_eq=$1
       break
       ;;
+    --messages=*)
+      if test -n "$messages"; then
+        fatal_error "Repeated option --messages."; fi
+      messages=$(expr "$1" : "[^=]*=\(.*\)")
+      ;;
+    --messages)
+      no_eq=$1
+      break
+      ;;
     -h | --help | -help)
       help=yes
       ;;
@@ -113,6 +122,7 @@ usage () {
 Usage: $(basename $0) [-h|--help]
                 --par-tokens=<par_tokens>.mly
                 --lex-tokens=<lex_tokens>.mli
+                --messages=<parser>.msg
                 --unlexer=<binary>
                 --ext=<extension>
                 --dir=<path>
@@ -135,6 +145,7 @@ Display control:
 Mandatory options:
       --lex-tokens=<name>.mli the lexical tokens
       --par-tokens=<name>.mly the syntactical tokens
+      --messages=<parser>.msg the complete errors messages
       --ext=EXT               Unix file extension for the
                               generated LIGO files
                               (no starting period)
@@ -160,6 +171,9 @@ fi
 
 # Checking options
 
+if test -z "$messages"; then
+  fatal_error "Messages not found (use --messages)."; fi
+
 if test -z "$unlexer"; then
   fatal_error "Unlexer binary not found (use --unlexer)."; fi
 
@@ -172,6 +186,9 @@ if test -z "$par_tokens"; then
 if test -z "$lex_tokens"; then
   fatal_error "No lexical tokens specification (use --lex-tokens)."; fi
 
+if test ! -e "$messages"; then
+  fatal_error "Error messages \"$messages\" not found (use messages.sh)."; fi
+
 if test ! -e "$parser"; then
   fatal_error "Parser specification \"$parser\" not found."; fi
 
@@ -218,12 +235,6 @@ if test "$ext_start" != "0"
 then fatal_error "LIGO extensions must not start with a period."
 fi
 
-# Checking the presence of the messages
-
-msg=$parser_base.msg
-if test ! -e $msg; then
-  fatal_error "File $msg not found."; fi
-
 # ====================================================================
 # Menhir's flags
 
@@ -233,7 +244,7 @@ flags="--table --strict --external-tokens $lex_tokens_base \
 # ====================================================================
 # Producing erroneous sentences from Menhir's error messages
 
-msg=$parser_base.msg
+msg=$messages
 raw=$parser_base.msg.raw
 printf "Making $raw from $msg... "
 menhir --echo-errors $parser_base.msg $flags $mly > $raw 2>/dev/null